Good , that's already a form of success.
Hi Everyone. After a short hiatus, I'm back to report on my progress.
After having gone through the procedure to un-brick my Seagate drive, here are the results.
I used a hot-swappable sort of enclosure to connect the drive to the computer. The computer could "see" the drive and the 5 partitions. It took a long time for the computer to "see" these partitions. Of the 5 partitions only one is readable and I was able to copy out my data to another external drive. Needless to say, the transfer rate was painfully slow, like 170 to 500 Kb/sec. I took about 3 days to finally transfer 90 Gb out.
Those is usually the behaviour of a "slow" disk (i.e. a disk that is going to fail soon), sometimes after the unbricking only a part of the disk is accessible, but that means that we are once again fundamentally "outside the scope" of this thread, i.e. your disk bricked itself for reasons different from the original firmware issue and only by pure coincidence the procedure, which is basically a "general reset" revived it.
The other 4 partitions could not be accessed, giving an error message as follows:
"Location is not available.
X O:\ is not accessible.
The request could not be performed because of an I/O device error."
Now tha tis not anymore bricked the issue becomes data recovery.
I think the above error message or the inability of the computer to access the other partitions is due to firmware problems.
Firmware has nothing to do with partitions, they are simply on a completely different "level", firmware is the lowest possible "physical" layer, on top of it there is the PC/OS "Physical layer" and on top of it there is the "logical layer" (to which volumes/partitions/filesystems belong).
What may happen is that there is a "limit" to the accessible sectors (but this is improbable that it is connected to firmware and more likely to be connected to hardware ).
Does anyone have any idea how to solve this problem?
(at least not in the DIY "club", professionals may)
The only thing that you can try doing is to image the disk (using any of the variously mentioned "suitable" tools, such as DMDE, DATARESCUEDD, etc.) and perform data recovery on the image (NOT on the original disk).
It is possible that this way you can recover more data than what you have till now, if you need help start a NEW thread, as that would go largely outside the scope of this one.